Recent reports have established that insects, like vertebrates, have iron-binding proteins, transferrin and ferritin. This suggests that iron metabolism in insects may be very similar to that in vertebrates. Therefore, the insect could be used as a model for studying iron metabolism, and the results could be applicable in vertebrate systems. Furthermore, a detailed study of the insect system will give new insights into strategies for insect control and for disrupting the interaction between parasites and insect disease vectors. We propose to: 1) characterize ferritin from Manduca sexta and develop molecular probes for it; 2) determine the presence and characteristics of transferrin receptors from tissue of this insect; 3) determine if the translational regulatory expression of ferritin and the transferrin receptor is similar to that of vertebrates; 4) search for ferritin receptors and characterize them; and 5) develop an in vitro insect tissue model for iron absorption. The molecular probes developed in this project will be used to explore iron metabolism in insects that are less amenable for biochemical studies, particularly mosquitoes.